Atjl nawiasky



. atented Sept. 20, 1932 2:.

UNITED STATES on LunwIGsHAnnn-on-mn-nnmn- GERMANY, nssrcnon TO NEW YORK, 1v.

PAUL NAWIASKY,

GENERAL ANILINE WORKS, INC., OF WARE No Drawing. Application filed July 9,

A considerable number of vat dyestuffs have the undesirable property of separating out, in the form of the alkaline earth metal salts of their hydrocompounds, when employed for dyeing in the presence of compounds of alkaline earth metals, as for example when hard water is used, the result being that the dyeings are substantially weaker than is the case with water which is free from calcium.

I have now found that this drawback is obviated, in a practially complete manner by adding phosphoric acid or water-soluble salts of the same to the vat dyestuffs themselves or to the bath liquor. The amounts of phosphoric acid or its salts to be added depend on the calcium content of the, dyebath and such amounts as are capable of binding the calcium ions in the dyebath are sufficient. When preparing compositions of matter comprising vat dyestuifs sensitive to the action of calcium *compounds which may be used in dye baths containing calcium salts rather large acid or a water-soluble salt thereof, for instance the same amount by weight as that r of the dyestuif employed, are incorporated with the vat dyestuflt'. It has been found that the action of phosphoric acid is substantially superior to that of other acids which form sparingly soluble alkaline earth metal salts, especially calcium salts, such as carbonic acid and oxalic acid. In practice, this is important in all cases where water of condensation is not available for dyeing, espec-ially when it is a matter of dyeing with mixtures of several dyestuffs, which difier in respect of their sensitiveness to calcium compounds.

The following examples will further illus- V trate the nature of the said invention which however is not limited thereto. The parts are by weight.

quantities of phosphoric QFFICE I Y., A CORPORATION OF DELA- IDYEING WITH VAT DYESTUFFS SENSITIVE TOGAIJCIUM GOMI'OUNDS 1928, Serial No. 291,496, and in Germany July 19, 1927.

Example 1 9 parts of an 11 per cent paste of brominated pyranthrone (see Schultz Farbstofl- Tabellen, 5th Ed, p. 61, No. 7 62) are mixed with 1 part of diammonium phosphate, an stirred until the salt is dissolved. A dyestuif paste is obtained which is practically insensitive to calcium compounds in dyeing from the vat.

Example 2 5 parts of the 'trichloranthraquinone-dihydroazine obtainable by the chlorination of dihydroanthraquinoneazine and subsequent treatment with alkaline hydrosulphite solution probably corresponding to O OQT U the formula:

are mixed, in a finely powdered state with 5 parts of disodium phosphate. Theresulting powder is practically insensitive, to calcium compounds in dyeing from the vat.

A similar procedure is adopted when a charge is prepared from the said dyestuff and a yellow dyestuff insensitive to calcium compounds, for example, the anthraquinonediphenyl-dithiazol from 2.6-diaminoanthraquinone (see U. S. Patent No. 1,095,731, Example 8). The dyeings obtained in this case are of the same greenish tinge whether the water used contains calcium or not,

whereas, in the absence of the added phosphate, a more yellowish tinge is obtained with water containing calcium.

' What I claim is I 1. A composition of matter comprising a vat dyestufi sensitive, in dyeing, to the ac tion of calcium compounds and a compound my hand.

PAUL N AWIASKY. 

